A 2K x 2K 10 µm cutoff HgCdTe array for background-limited space astronomy has been developed by Teledyne Imaging Sensors to specifications set by JPL, and demonstrated by University of Rochester at a focal plane temperature of 40K for the proposed JPL Near-Earth Object Camera (NEOCam) survey mission under the NASA Planetary Defense Coordination Office. We describe the detector performance for the first large format monolithic HgCdTe detector array tested, including the dark current, well depth, dark current vs. temperature, quantum efficiency, latent image performance, and read noise.

Rochester Institute of Technology (RIT) and its collaborators at the University of Rochester and Harris Corporation are developing a room-temperature imaging Terahertz (THz) frequency detector using Si-MOSFET (Silicon Metal Oxide Semiconductor Field Effect Transistor) CMOS devices. They are implemented into a focal plane imaging array for use in many applications, such as transmission or penetration imaging and spectroscopy. Technology for THz detection is often extremely costly, due to either expensive detector materials or cryogenic cooling systems. However, the devices tested here are low-cost due to the use of conventional room temperature silicon CMOS technology. The devices operate from 170 to 250 GHz with an additional detector design has been fabricated for 30 THz (10 microns wavelength). Results are presented for the initial testing of single test structure FETs. These devices were designed with several different antenna configurations and a range of MOSFET design variations for evaluation. The primary goal of the work presented here is to determine the optimized detector design for the subsequent focal plane array implementation based on the largest responsivities and lowest noise-equivalent power (NEP). Transmission testing of the devices yields responsivities of about 100 to 1000 V/W and a NEP of about 0.5 to 10 nW·Hz<sup>-1/2</sup>. Through this evaluation and by utilizing signal amplification on the chip, signal modulation at higher frequencies, and smaller process sizes the performance of these devices will continue to improve in future designs.

HgCdTe detector arrays with a cutoff wavelength of ∼10 μm intended for the Near-Earth Object Camera (NEOCam) space mission were subjected to proton-beam irradiation at the University of California Davis Crocker Nuclear Laboratory. Three arrays were tested—one with 800-μm substrate intact, one with 30-μm substrate, and one completely substrate-removed. The CdZnTe substrate, on which the HgCdTe detector is grown, has been shown to produce luminescence in shorter wave HgCdTe arrays that causes an elevated signal in nonhit pixels when subjected to proton irradiation. This testing was conducted to ascertain whether or not full substrate removal is necessary. At the dark level of the dewar, we detect no luminescence in nonhit pixels during proton testing for both the substrate-removed detector array and the array with 30-μm substrate. The detector array with full 800-μm substrate exhibited substantial photocurrent for a flux of 103 protons/cm2 s at a beam energy of 18.1 MeV (∼750 e−/s) and 34.4 MeV (∼65 e−/s). For the integrated space-like ambient proton flux level measured by the Spitzer Space Telescope, the luminescence would be well below the NEOCam dark current requirement of <200 e−/s, but the pattern of luminescence could be problematic, possibly complicating calibration.

The Near Earth Object Camera (NEOCam, Mainzer et al. 2015) is one of five NASA Discovery Class mission
experiments selected for Phase A: down-select to one or two experiments will take place late in 2016. NEOCam will
survey the sky in search of asteroids and comets, particularly those close to the Earth’s orbit. The NEOCam infrared
telescope will have two infrared (IR) channels; one covering 4 to 5 microns, and one covering 6-10 microns. Both IR
cameras will use multiple 2Kx2K pixel format HAWAII-2RG arrays with different cutoff wavelength HgCdTe detectors
from Teledyne Imaging Sensors. Past development work by the University of Rochester with Teledyne Imaging Sensors
and JPL (McMurtry et al. 2013, Dorn et al. 2016) focused upon bringing the 10 micron HgCdTe detector technology up
to NASA TRL 6+. This work extends that development program to push the format from 1Kx1K to the larger 2Kx2K
pixel array. We present results on the first 2Kx2K candidate 10 micron cutoff HgCdTe arrays, where we measured the
dark current, read noise, and total noise.

With the recent success of our development of 10 micron HgCdTe infrared (IR) detector arrays,<sup>1,2</sup> we have used what we learned and extended the cutoff wavelength to 13 microns. These 13 micron HgCdTe detector arrays can operate at higher temperatures than Si:As, e.g. in a properly designed spacecraft with passive cooling, the 13 micron IR array will work well at temperatures around 30K. We present the initial measurements of dark current, noise and quantum efficiency for the first deliveries of 13 micron HgCdTe detector arrays from Teledyne Imaging Sensors. We also discuss our plans to develop 15 micron cutoff HgCdTe detector arrays which would facilitate the detection of the broad CO<sub>2</sub> absorption feature in the atmospheres of exoplanets, particularly those in the habitable zone of their host star.

Collaboration between Exelis Geospatial Systems with University of Rochester and Rochester Institute of Technology aims to develop an active THz imaging focal plane array utilizing 0.35um CMOS MOSFET technique. An appropriate antenna is needed to couple incident THz radiation to the detector which is much smaller than the wavelength of interest. This paper simply summarizes our work on modeling the optical characteristics of bowtie antennae to optimize the design for detection of radiation centered on the atmospheric window at 215GHz. The simulations make use of the finite difference time domain method, calculating the transmission/absorption responses of the antenna-coupled detector.

Exelis Geospatial Systems and its CEIS partners at the University of Rochester and Rochester Institute of Technology are developing an active THz imaging system for use in standoff detection, molecular spectroscopy and penetration imaging. The current activity is focused on developing a precision instrument for the detection of radiation centered on atmospheric windows between 200 GHz and 400 GHz (available sources). A transmission imager is developed by raster scanning through a semi-coherent non-ionizing beam, where the beam is incident on a NMOS FET detector. The primary goal of the initial system is to produce a setup capable of measuring responsivity and sensitivity of the detector. The Instrumentation covers the electromagnetic spectral range between 188 GHz and 7.0 THz. Transmission measurements are collected at 188 GHz in order to verify image formation, responsivity and sensitivity as well as demonstrate the active imager’s ability to make penetration images.

We have investigated the response of 10 micron cutoff HgCdTe 1024 &times; 1024 pixel arrays, grown by Teledyne Imaging Sensors (TIS) on CdZnTe substrates, to ionizing radiation in the form of galactic cosmic ray secondaries near sea level, primarily muons, and natural radiation. The arrays are optimized for use in space observatories, such as the proposed NEOCam mission, so response to ubiquitous cosmic rays is crucially important. We analyzed 2000 6-second integration samples, for each pixel in each array, to characterize their response to ionizing radiation. Muons and other ionizing radiation leave 'footprints' in the data, visible as a sudden 'jump' in signal in the time series, which affects a cluster of pixels simultaneously. We investigated 4 key properties of these radiation hits: the number of pixels affected in each cluster, the charge generated by the event, the detector noise directly after the hit, and the responsivity of the pixel before and after each hit. The responsivity (plus dark current), given by the slope of the time series, was unaffected by the radiation hits. Likewise the correlated-double-sampling read noise was unaffected by the hits. The total charge generated was in reasonable agreement with that expected from 2-4 GeV muon hits. 8-12 pixels were typically affected by single hits, irrespective of the thickness of the CdZnTe substrate (800, 48 and zero microns). This cluster size was significantly larger than that observed in a 2.5 micron cutoff array from TIS, but similar to that shown by a 5 micron cutoff device from TIS tested for response to energetic protons for the JWST mission.

The James Webb Space Telescope Fine Guidance Sensor makes use of three 2048&times;2048 five micron cutoff H2RG HgCdTe detectors from Teledyne Imaging Systems. The FGS consists of two Guider channels and a Near-InfraRed Imager and Slitless Spectrograph (NIRISS) channel. We report here on detailed tests results from the Guider channels originating in both instrument level performance testing and from recent Guider performance testing with the FGS integrated into JWST’s Integrated Science Instrument Module (ISIM). A key performance parameter is the noise equivalent angle (NEA) or centroiding precision. The JWST requirement flowed down to the Guiders is a NEA of 4 milli-arcseonds, equivalent to approximately 1/20<sup>th</sup> of a detector pixel. This performance has been achieved in the testing to date. We have noted a systematic asymmetry in the NEA depending on whether the NEA in the row or column direction is considered. This asymmetry depends on guide star brightness and reaches its maximum, where the row NEA is 15% to 20% larger than the column NEA, at the dim end of the Guide star brightness range. We evaluate the detector level characteristics of spatially correlated noise and asymmetric inter-pixel capacitance (IPC) as potential sources of this NEA asymmetry. Modelling is used to estimate the impact on NEA of these potential contributors. These model results are then compared to the Guider test results obtained to date in an effort to isolate the cause of this effect. While asymmetric IPC can induce asymmetric NEA, the required magnitude of IPC is far greater than observed in these detectors. Thus, spatially correlated noise was found to be the most likely cause of the asymmetric NEA.

Exelis Geospatial Systems and its CEIS partners at the University of Rochester and Rochester Institute of Technology
are developing an active THz imaging focal plane for use in standoff detection, molecular spectroscopy and penetration
imaging. This activity is focused on the detection of radiation centered on the atmospheric window at 215.5 GHz. The
pixel consists of a direct coupled bowtie antenna utilizing a 0.35 μm CMOS technology MOSFET, where the plasmonic
effect is the principle method of detection. With an active THz illumination source such as a Gunn diode, a design of
catadioptric optical system is presented to achieve a resolution of 3.0 mm at a standoff distance of 1.0 m. The primary
value of the initial system development is to predict the optical performance of a THz focal plane for active imaging and
to study the interaction of THz radiation with various materials.

Interest in array based imaging of terahertz energy (T-Rays) has gained traction lately, specifically using a CMOS process due to its ease of manufacturability and the use of MOSFETs as a detection mechanism. Incident terahertz radiation on to the gate channel region of a MOSFET can be related to plasmonic response waves which change the electron density and potential across the channel. The 0.35 &mu;m silicon CMOS MOSFETs tested in this work contain varying structures, providing a range of detectors to analyze. Included are individual test transistors for which various operating parameters and modes are studied and results presented. A focus on single transistor-antenna testing provides a path for discovering the most efficient combination for coupling 0.2 THz band energy. An evaluation of fabricated terahertz band test detection MOSFETs is conducted. Sensitivity analysis and responsivity are described, in parallel with theoretical expectations of the plasmonic response in room temperature conditions. A maximum responsivity of 40 000 V/W and corresponding NEP of 10 pW/Hz<sup>1/2</sup> (&plusmn;10% uncertainty) is achieved.

We describe preliminary design, modeling and test results for the development of a monolithic, high pixel density,
THz band focal plane array (FPA) fabricated in a commercial CMOS process. Each pixel unit cell contains multiple
individual THz band antennae that are coupled to independent amplifiers. The amplified signals are summed either
coherently or incoherently to improve detection (SNR). The sensor is designed to operate at room temperature using
passive or active illumination. In addition to the THz detector, a secondary array of Visible or SWIR context
imaging pixels are interposed in the same area matrix. Multiple VIS/SWIR context pixels can be fabricated within
the THz pixel unit cell. This provides simultaneous, registered context imagery and "Pan sharpening" MTF
enhancement for the THz image. The compact THz imaging system maximizes the utility of a ~ 300 &mu;m x 300 &mu;m
pixel area associated with the optical resolution spot size for a THz imaging system operating at a nominal ~ 1.0
THz spectral frequency. RF modeling is used to parameterize the antenna array design for optimal response at the
THz frequencies of interest. The quarter-wave strip balanced bow-tie antennae are optimized based on the
semiconductor fabrication technology thin-film characteristics and the CMOS detector input impedance. RF SPICE
models enhanced for THz frequencies are used to evaluate the predicted CMOS detector performance and optimal
unit cell design architecture. The models are validated through testing of existing CMOS ROICs with calibrated THz
sources.

The near-earth object camera (NEOCam) is a proposed infrared space mission designed to discover and characterize most of the potentially hazardous asteroids larger than 140 m in diameter that orbit near the Earth. NASA has funded technology development for NEOCam, including the development of long wavelength infrared detector arrays that will have excellent zodiacal background emission-limited performance at passively cooled focal plane temperatures. Teledyne Imaging Sensors has developed and delivered for test at the University of Rochester the first set of approximately 10 μm cutoff, 1024×1024 pixel HgCdTe detector arrays. Measurements of these arrays show the development to be extremely promising: noise, dark current, quantum efficiency, and well depth goals have been met by this technology at focal plane temperatures of 35 to 40 K, readily attainable with passive cooling. The next set of arrays to be developed will address changes suggested by the first set of deliverables.

The Fine Guidance Sensor (FGS) is one of the four science instruments on board the James Webb Space Telescope (JWST). FGS features two modules: an infrared camera dedicated to fine guiding of the observatory and a science camera module, the Near-Infrared Imager and Slitless Spectrograph (NIRISS) covering the wavelength range between 0.7 and 5.0 &mu;m with a field of view of 2.2' X 2.2'. NIRISS has four observing modes: 1) broadband imaging featuring seven of the eight NIRCam broadband filters, 2) wide-field slitless spectroscopy at a resolving power of rv150 between 1 and 2.5 &mu;m, 3) single-object cross-dispersed slitless spectroscopy enabling simultaneous wavelength coverage between 0. 7 and 2.5 &mu;m at Rrv660, a mode optimized for transit spectroscopy of relatively
bright (J &gt; 7) stars and, 4) sparse aperture interferometric imaging between 3.8 and 4.8 &mu;m enabling high­
contrast ("' 10<sup>-4</sup>) imaging of M &lt; 8 point sources at angular separations between 70 and 500 milliarcsec. This
paper presents an overview of the FGS/NIRISS design with a focus on the scientific capabilities and performance offered by NIRISS.

Using band-limited LASER speckle to measure the Modulation Transfer Function (MTF) of an image
sensor offers simplified procedure and inexpensive laboratory set up compared with the traditional method
of using a knife edge on the sensor imaging plane. This speckle technique has been previously
demonstrated by Glen Boreman's group on devices in the visible range. We have extended the procedure
to short-wave infrared (IR) sensor at 1.55 micron. Similar measurements were also made at 532 nanometer
on a commercial visible (VIS) sensor. The experiments show that the LASER speckle method to be
accurate when compared to knife-edge measurements for data below Nyquist. The measured MTF data
support optical system design and image quality modeling for both VIS and IR sensing applications.

The development and testing of thermal signature tracking algorithms burdens the developer with a method
of testing the algorithm's fidelity. Although actual video is normally used for testing tracking algorithms, to
evaluate performance in a variety of configurations, the acquisition of suitable video data volume is
prohibitive. As an alternative to actual video we are developing accurate synthetic thermal infrared models
of vehicles that will be incorporated into background infrared images generated using the Digital Image and
Remote Sensing Image Generation (DIRSIG) software package. Motion for the targets within the
background scene is generated using the open-source Simulation of Urban MObility (SUMO<sup>TM</sup>) software
package. ThermoAnalytics' Multi-Service Electro-optic Signature (MuSES<sup>TM</sup>) software package is used to
model thermal emission from the object of interest. The goal is to accurately incorporate thermal signatures
of moving targets into realistic radiometrically calibrated scenes, and to then test and evaluate tracking
algorithms using both visible and thermal infrared signatures for improved day and night detection
capability. The software packages have been integrated together for a synthetic video

The Fine Guidance Sensor (FGS) of the James Webb Space Telescope (JWST) features a tunable filter imager (TFI)
module covering the wavelength range from 1.5 to 5.0 &mu;m at a resolving power of ~100 over a field of view of
2.2'&times;2.2'. TFI also features a set of occulting spots and a non-redundant mask for high-contrast imaging. This paper
presents the current status of the TFI development. The instrument is currently under its final integration and test phase.

In recent years, Teledyne Imaging Sensors has begun development of Long Wave Infrared (LWIR) HgCdTe
Detector Arrays for low background astronomical applications, which have a high percentage of low dark current
pixels but a substantial high dark current tail. Characterization of high dark current pixels in these devices has
produced I-V curves with unusual behaviors. The typical theories of diffusion current, tunneling current, and
even surface current have been unable to accurately model the observed I-V curves. By modeling dislocations in
and near the <i>p-n</i> junction as trapping sites and those near the surface as leakage channels, the behavior of these
unusual I-V curves is successfully modeled, pointing to the need to reduce the number of these dislocations in
order to produce LWIR HgCdTe photodiodes exhibiting very low dark current with sufficient well depth.

We describe the construction and commissioning of FIRE, a new 0.8-2.5&mu;m echelle spectrometer for the Magellan/
Baade 6.5 meter telescope. FIRE delivers continuous spectra over its full bandpass with nominal spectral
resolution R = 6000. Additionally it offers a longslit mode dispersed by the prisms alone, covering the full z to
K bands at R ~ 350. FIRE was installed at Magellan in March 2010 and is now performing shared-risk science
observations. It is delivering sharp image quality and its throughput is sufficient to allow early observations of
high redshift quasars and faint brown dwarfs. This paper outlines several of the new or unique design choices
we employed in FIRE's construction, as well as early returns from its on-sky performance.

The Fine Guidance Sensor (FGS) of the James Webb Space Telescope (JWST) features a tunable filter imager (TFI)
module covering the wavelength range from 1.6 to 4.9 &mu;m at a resolving power of ~100 over a field of view of
2.2'x2.2'. TFI also features a set of 4 occulting spots for coronagraphy. A review of the current design and development
status of TFI is presented along with two key TFI science programs: the detection of first light, high-redshift Ly&alpha;
emitters and the detection/characterization of exoplanets.

FIRE (the Folded-port InfraRed Echellette) is a prism cross-dispersed infrared spectrometer, designed to deliver singleobject
R=6000 spectra over the 0.8-2.5 micron range, simultaneously. It will be installed at one of the auxiliary
Nasmyth foci of the Magellan 6.5-meter telescopes. FIRE employs a network of ZnSe and Infrasil prisms, coupled with
an R1 reflection grating, to image 21 diffraction orders onto a 2048 &times; 2048, HAWAII-2RG focal plane array.
Optionally, a user-controlled turret may be rotated to replace the reflection grating with a mirror, resulting in a singleorder,
longslit spectrum with R ~ 1000. A separate, cold infrared sensor will be used for object acquisition and guiding.
Both detectors will be controlled by cryogenically mounted SIDECAR ASICs. The availability of low-noise detectors
motivates our choice of spectral resolution, which was expressly optimized for Magellan by balancing the scientific
demand for increased R with practical limits on exposure times (taking into account statistics on seeing conditions).
This contribution describes that analysis, as well as FIRE's optical and opto-mechanical design, and the design and
implementation of cryogenic mechanisms. Finally, we will discuss our data-flow model, and outline strategies we are
putting in place to facilitate data reduction and analysis.

During the expected 5+ years of operation, the Spitzer Space Telescope is and will continue to produce outstanding infrared images and spectra, and greatly further scientific understanding of our universe. The Spitzer Space Telescope's instruments are cryogenically cooled to achieve low dark current and low noise. After the cryogens are exhausted, the Spitzer Space Telescope will only be cooled by passively radiating into space. The detector arrays in the IRAC instrument are expected to equilibrate at approximately 30K. The two shortest wavelength channels (3.6 and 4.5 micron) employ InSb detector arrays and are expected to function and perform with only a modest degradation in sensitivity. Thus, an extended mission is possible for Spitzer. We present the predicted dark current, noise, quantum efficiency and image residuals for the 3.6 and 4.5 micron IRAC channels in the post-cryogen era.

The James Webb Space Telescope (JWST) will have several on-board instruments, of which the Mid-Infrared Instrument (MIRI) will cover imaging and low resolution spectroscopy in the 5-28 micron region. To achieve the many science goals for MIRI, the detector arrays must be capable of achieving high sensitivity. The primary obstacle to high sensitivity is the total noise. The total noise is often dominated by two main parts: the read noise of the multiplexer and the shot noise of the detector array's dark current. We present recent results of the measured read noise for several candidate multiplexers from the first Si-foundry run.

Burst noise (also known as popcorn noise and random telegraph signal/noise) is a phenomenon that is understood to be a result of defects in the vicinity of a p-n junction. It is characterized by rapid level shifts in both positive and negative directions and can have varying magnitudes. This noise has been seen in both HAWAII-1RG and HAWAII-2RG multiplexers and is under investigation. We have done extensive burst noise testing on a HAWAII-1RG multiplexer, where we have determined a significant percentage of pixels exhibit the phenomenon. In addition, the prevalence of small magnitude transitions make sensitivity of detection the main limiting factor. Since this is a noise source for the HAWAII-1RG multiplexer, its elimination would make the HAWAII-1RG and the HAWAII-2RG even lower noise multiplexers.

With the introduction of the Raytheon 2.5 micron HgCdTe VIRGO detector array, some astronomy programs, such as the VISTA Program, are turning to Raytheon for near infrared detector arrays. We characterize one VIRGO detector array and provide results of measurements at low backgrounds including dark current, read noise, total noise, quantum efficiency, and operability. The Raytheon VIRGO HgCdTe detector arrays are excellent candidates for many low background astronomical programs, including space-borne telescope missions.

Future infrared space missions will undoubtedly employ passively cooled focal plane arrays (T ~ 30K), as well as passively cooled telescopes. Most long-wave detector arrays (e.g. Si:As IBC) require cooling to temperatures of ~ 6-8K. We have been working with Rockwell Scientific Company to produce <= 10 micron cutoff HgCdTe detector arrays that, at temperatures of ~30K, exhibit sufficiently low dark current and sufficiently high detective quantum efficiency, as well as high uniformity in these parameters, to be interesting for astronomy. Our goal is to achieve dark current below the target
value of ~ 30 e-/s/pixel with at least 60mV of actual reverse bias across the diodes at T ~ 30K. To this end, Rockwell Scientific Company has delivered three 10 micron cutoff HgCdTe low dark current detector arrays with small capacitance diodes for characterization in Rochester. The most recent presentation showed the remarkable preliminary performance of the first of these devices. We present further results on the first device along with results on the subsequent two deliveries.

We describe the astronomical observation template (AOT) for the Infrared Array Camera (IRAC) on the Spitzer Space Telescope (formerly SIRTF, hereafter Spitzer). Commissioning of the AOTs was carried out in the first three months of the Spitzer mission. Strategies for observing fixed and moving targets are described, along with the performance of the AOT in flight. We also outline the operation of the IRAC data reduction pipeline at the Spitzer Science Center (SSC) and describe residual effects in the data due to electronic and optical anomalies in the instrument.

The Infrared Array Camera (IRAC) is one of three focal plane instruments on board the Spitzer Space Telescope. IRAC is a four-channel camera that obtains simultaneous broad-band images at 3.6, 4.5, 5.8, and 8.0 &#956;m in two nearly adjacent fields of view. We summarize here the in-flight scientific, technical, and operational performance of IRAC.

The Infrared Array Camera (IRAC) on Spitzer Space Telescope includes four Raytheon Vision Systems focal plane arrays, two with InSb detectors, and two with Si:As detectors. A brief comparison of pre- flight laboratory results vs. in-flight performance is given, including quantum efficiency and noise, as well as a discussion of irregular effects, such as residual image performance, "first frame effect", "banding", "column pull-down" and multiplexer bleed. Anomalies not encountered in pre-flight testing, as well as post-flight laboratory tests on these anomalies at the University of Rochester and at NASA Ames using sister parts to the flight arrays, are emphasized.

Future infrared space missions will undoubtedly employ passively cooled focal plane arrays (T ~ 30K), as well as passively cooled telescopes. Most long-wave detector arrays (e.g. Si:As IBC) require cooling to temperatures of ~ 6-8K. We have been working with Rockwell Scientific Company to produce &ge; 10 &mu;m cutoff HgCdTe detector arrays that, at temperatures of ~ 30K, exhibit sufficiently low dark current and sufficiently high detective quantum efficiency, as well as high uniformity in these parameters, to be interesting for astronomy. Our goal is to achieve dark current below the target value of ~30 e-/s/pixel with at least 60mV of actual reverse bias across the diodes at T ~ 30K. To this end, Rockwell Scientific Company has delivered the first array in a new order, for characterization in Rochester. Recent array deliveries of 10&mu;m cutoff HgCdTe bonded to a Hawaii-1RG multiplexer utilize the smallest capacitance diode type. We present preliminary results on this latest 10 &mu;m cutoff HgCdTe low dark current detector array.

The James Webb Space Telescope (JWST), the successor to the Hubble Space Telescope, will draw on recent improvements in infrared array technologies to achieve its goals and mission. In order to best meet the goals of JWST, NASA is funding a competition between two near infrared detector technologies: InSb detector arrays from Raytheon Vision Systems and HgCdTe detector arrays from Rockwell Scientific. The University of Rochester, in collaboration with Raytheon, is testing near infrared InSb detectors in a 2048 x 2048 array format
to meet the stringent requirements for JWST. Results from characterization under top level requirements, such as noise, quantum efficiency, well capacity, pixel operability, etc., are discussed. Dark current and its contribution to the total noise are analyzed.

The Infrared Array Camera (IRAC) is one of three focal plane instruments in the Space Infrared Telescope Facility (SIRTF). IRAC is a four-channel camera that obtains simultaneous images at 3.6, 4.5, 5.8, and 8 microns. Two adjacent 5.12x5.12 arcmin fields of view in the SIRTF focal plane are viewed by the four channels in pairs (3.6 and 5.8 microns; 4.5 and 8 microns). All four detector arrays in the camera are 256x256 pixels in size, with the two shorter wavelength channels using InSb and the two longer wavelength channels using Si:As IBC detectors. We describe here the results of the instrument functional and calibration tests completed at Ball Aerospace during the integration with the cryogenic telescope assembly, and provide updated estimates of the in-flight sensitivity and performance of IRAC in SIRTF.

Future infrared space missions will undoubtedly employ passively cooled focal planes (T ~ 30K), as well as passively cooled telescopes. Most long-wave detector arrays (e.g. Si:As IBC) require cooling to temperatures of ~ 6-8K. We have been working with Rockwell to produce 10&mu;m cutoff HgCdTe detector arrays that, at temperatures of ~ 30K, exhibit sufficiently low dark current and sufficiently high detective quantum efficiency to be interesting for astronomy. In pursuit of these goals, Rockwell Scientific Company has delivered twelve 256 x 256 arrays (several of them engineering arrays), with cutoff wavelengths at 30K between 7.4 and 11&mu;m for characterization at Rochester. Seven of these arrays utilize advanced structure diodes with differing capacitances arranged in rows (banded arrays), and the materials properties of the HgCdTe also vary significantly from array to array. Of ultimate interest to astronomy is the fraction of pixels with dark current below the target value of ~ 100e<sup>-</sup>/s with 10-60mV of actual reverse bias across the diodes at T ~ 30K. These arrays were developed for the purpose of selecting diode architecture: we use this fraction as one criterion for selection. We have determined from these experiments the optimal diode architecture for future array development. Measurement of the dark current as a function of reverse bias and temperature allows us to ascertain the extent to which trap-to-band tunneling dominates the dark current at this temperature. We present the results for one representative array, UR008.

The astronomical community has benefited from the scientific advances in photo-detection over the last few decades, from optical CCDs to infrared array detectors, for both large ground-based telescopes and space-borne telescopes. NGST, the successor to the Hubble Space Telescope, will draw on the improvements in infrared array technologies to achieve its goals and mission. The University of Rochester, in collaboration with Raytheon and NASA Ames Research Center, is developing and testing near infrared InSb array detectors to meet the stringent requirements for NGST. The latest development involves a suitable multiplexer in a 2048 x 2048 format that will be bump-bonded to an InSb array. Twenty of these arrays will be required for NGST imaging and spectroscopy. We present results for pathfinder 1024 x 1024 arrays. This is a companion work to the paper in these SPIE proceedings by Ken Ando, Peter Love, Nancy Lum, Alan Hoffman, Roger Holcombe, John Durkee, Joseph Rosbeck, and Elizabeth Corrales (Raytheon Infrared Operations).

The Infrared Array Camera (IRAC) is one of three focal plane instruments in the Space Infrared Telescope Facility (SIRTF). IRAC is a four-channel camera that obtains simultaneous images at 3.6, 4.5, 5.8, and 8 microns. Two adjacent 5.12 X 5.12 arcmin fields of view in the SIRTF focal plane are viewed by the four channels in pairs (3.6 and 5.8 microns; 4.5 and 8 microns). All four detectors arrays in the camera are 256 X 256 pixels in size, with the two shorter wavelength channels using InSb and the two longer wavelength channels using Si:As IBC detectors. We describe here the results of the instrument functionality and calibration tests completed at Goddard Space Flight Center, and provide estimates of the in-flight sensitivity and performance of IRAC in SIRTF.

SIRTF requires detector arrays with extremely high sensitivity, limited only by the background irradiance. Especially critical is the near infrared spectral region around 3 micrometers , where the detector current due to the zodiacal background is a minimum. IRAC has two near infrared detector channels centered at 3.6 and 4.5 micrometers . We have developed InSb arrays for these channels that operate with dark currents of &lt; 0.2 e/s and multiply-sampled noise of approximately 7 e at 200 s exposure. With these specifications the zodiacal background limited requirements has been easily met. In addition, the detector quantum efficiency of the InSb devices exceeds 90% over the IRAC wavelength range, they are radiation hard, and they exhibit excellent photometric accuracy and stability. Residual images have been minimized. The Raytheon 256 X 256 InSb arrays incorporate a specially developed (for SIRTF) multiplexer and high-grade InSb material.

Spatial distributions of hole trap sites on a quasipixel level in InSb arrays for SIRTF are examined. The dependence of flux, fluence, and applied bias on image latency is investigated, and experimental results are presented and discussed. Models of linearity and capacitance are compared with experimental results. We find increasing the depletion width in a light exposed pixel by larger reverse biasing decreases the trapped charge (or latency) in that pixel by factors of approximately 3. Assumed pixel geometries lead to an apparent spatial density of active trap sites that falls quickly with distance from the implants.

This paper summarizes the findings of the Next Generation Space Telescope (NGST) Detector Requirements Review Panel. This panel was comprised of NGST Integrated Science Instrument Module study representatives, detector specialists, and members of the NGST project science team. It has produced a report that recommends detector performance levels, and has provided rationale for deriving these levels from basic, anticipated NGST science goals and programs. Key parameters such as detector array format, quantum efficiency, and noise are discussed and prioritized.

We describe the design and performance of the near IR telescope experiment (NITE), a rocket-borne instrument designed to search for IR emission from baryonic dark matter in the halos of nearby edge-on spiral galaxies. A 256 X 256 InSb array at the focus of a 16.5 cm liquid-helium- cooled telescope achieves near-background-limited sensitivity in a 3.5-5.5 micrometers waveband where the local foreground from zodiacal emission is at a minimum. This experiment represents the first scientific application of a low-background IR InSb array, a precursor to the InSb arrays intended for SIRTF, in a space-borne observation. We describe the flight performance of the instrument and preliminary scientific result from an observation of NGC 4565.

The Space IR Telescope Facility (SIRTF) contains three focal plane instruments, one of which is the IR Array Camera (IRAC). IRAC is a four-channel camera that provides simultaneous 5.12 X 5.12 arcmin images at 3.6, 4.5, 5.8 and 8 microns. The pixel size is 1.2 arcsec in all bands. Two adjacent fields of view in the SIRTF focal plane are viewed by the four channels in pairs. All four detector arrays in the camera are 256 by 256 pixels in size, with the two short wavelength channels using InSb and the two longer wavelength channels using Si:As IBS detectors. The IRAC sensitivities at 3.6, 4.5, 5.8, and 8.0 microns are 6, 7, 36, and 54 microJanskys, respectively. Two of the most important scientific objectives of IRAC will be to carry out surveys to study galaxy formation and evolution during the early stage of the Universe, and to search for brown dwarfs and superplanets.

This paper is a review of current astronomy projects at Raytheon/SBRC in the near-IR band. Another paper in this same session (3354-11) covers astronomy projects in longer wavelengths. For ground-based astronomy, InSb arrays with formats of 256 X 256, 512 X 512, and 1024 X 1024 have been developed and tested. For space-based astronomy, four projects are discussed with array formats ranging from 256 X 256 to 2K X 2K. The space projects support instruments on the SIRTF, IRIS, NGST, and Rosetta missions. Representative data are presented from 1024 X 1024 and 256 X 256 arrays obtained by test facilities at NOAO and the University of Rochester.

Rockwell Science Center has developed a double layer planar heterostructure (DLPH) detector array fabrication process with significant advantages over the PACE-1 process now being used to produce 256 X 256 and 1024 X 1024 FPAs for low background IR astronomy. The DLPH detectors are p- on-n photodiodes fabricated in a double layer of wide and narrow bandgap HgCdTe grown by molecular beam epitaxy on CdZnTe substrates. The double layer structure provides superior surface passivation while the lattice matched CdZnTe substrate reduces the defect density. DLPH FPAs have been fabricated in array sizes up to 640 X 480 and with cutoff wavelengths as long as 15 micrometers . Quantum efficiencies are typically in the 0.5 to 0.8 range. For a 256 X 256 array DLPH detectors with 5.3 micrometers cutoff wavelength at 50K, the median dark current was 0.39 e-/sec at 0.5V reverse bias. For 7 of 17 individual DLPH detector with 10.6 micrometers cutoff at 30K, the dark current was less than 10<SUP>4</SUP> e-/sec at 20 mV bias. For long cutoff wavelengths, the detector breakdown voltage is too low to permit signal integration directly on the reverse biased detector capacitance. Such detectors require a readout circuit that maintains the detector near zero bias and provides a separate capacitor to store the integrated signal.

SIRTF, and other infrared space astronomy projects, require detector arrays with extremely high sensitivity. It is a goal of SIRTF to achieve background limited performance at all wavelengths. Especially critical is the spectral region around 3 micrometers , where the zodiacal dust emission and scattering reaches a minimum, and where there are no other natural background sources, and where a cooled space telescope provides negligible background. This is a spectral region where many of the most interesting astrophysical sources can best be studied. The IRAC (infrared array camera) SIRTF experiment requires short wavelength detector arrays (2 - 5 micrometers ) that achieve background limited operation.

SIRTF, and other infrared space astronomy projects, require detector arrays with extremely high sensitivity. It is a goal of SIRTF to achieve background limited performance at all wavelengths. Especially critical is the spectral region around 3 micrometers , where the detector current due to the zodiacal background radiation is a minimum. For background limited operation, at a spectral resolution of 100, the dark current must be less than 0.1 e<SUP>-</SUP>/s/pixel. The detector noise must be less than the noise given by fluctuations in the number of zodiacal background photons (&lt; 9 e<SUP>-</SUP>/pixel). Other detector array goals include: high quantum efficiency (&gt; 90%), radiation hardness, minimal image latency, and excellent photometric accuracy and stability. Many of the performance goals have been met with Santa Barbara Research Center's 256 X 256 InSb arrays.

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